The U.S. is in the midst of an epidemic of chronic kidney disease. The incidence of treated end stage renal disease (ESRD) has risen every year since Medicare began collecting such information in 1973. In 2002, over 500,000 persons in the U.S. were treated for ESRD and about 20 million persons are estimated to have chronic kidney disease. Thus, chronic kidney disease is a major clinical and public health problem that demands our utmost attention. The present application is a renewal request for a K-24 award that the PI received in 2000. The PI is an established leader in the epidemiology and prevention of kidney disease who has an outstanding record of accomplishments in mentorship and conduct of patient-oriented research. The focus of his work has been to understand better the reasons for the excess risk of cardiovascular disease in persons with treated ESRD and milder forms of kidney disease. During the last 4 years, the PI has mentored 19 trainees and junior faculty and published 51 articles, 43 of which are peer-reviewed manuscripts, 25 of which have mentees as first author. Mentorship is accomplished through a rigorous didactic training program coupled with a mentored research experience and intensive involvement in federally-funded research projects. Training takes place within a very rich research environment and trainees are supported through institutional training grants as well as individual grants. A number of research opportunities exist for trainees;this application details a new cohort study of 1,000 treated ESRD patients from the Baltimore area who will be followed for up to 4 years to determine risk factors (traditional cardiovascular disease, dialysis-related, and genetic risk factors) for sudden cardiac death (SCD). ESRD patients are at very high risk of SCD, equivalent to persons who are post-myocardial infarction. This study will not only provide data to reduce the risk of this untoward event but will also provide a rich infrastructure for future studies, including clinical trials, and for research training.